In the integrated circuit manufacturing process, integrated circuit devices, such as transistors, are first formed at the surface of a semiconductor substrate in a wafer. An interconnect structure is then formed over the integrated circuit devices. Metal pads are formed over, and are electrically coupled to, the interconnect structure. A passivation layer and a first polymer layer are formed on the metal pads, with the metal pads exposed through the openings in the passivation layer and the first polymer layer. A Post-Passivation Interconnect (PPI) structure is then formed, which includes redistribution lines connected to the metal pads. A second polymer layer is then formed over the PPI. Under-Bump-Metallurgies (UBMs) are formed to extend into the openings in the second polymer layer, wherein the UBMs are electrically connected to the PPI. Solder balls are then placed over the UBMs and reflowed.
The wafer is then sawed. Since the wafer includes a plurality of layers formed of different materials, if the wafer is sawed directly, the plurality of layers may delaminate. To prevent the delamination between the plurality of layers in the wafer, a laser grooving is first performed on the scribe lines in order to remove the layers that are subject to delamination. In order to perform the laser grooving, a protection layer is formed on the wafer. The Laser grooving is then performed. During the laser grooving, the debris generated by the laser grooving may fall on the protection layer. After the laser grooving, the protection layer is removed along with the debris thereon. The formation and the removal of the protection layer result in additional manufacturing cost.